Welcome to LookChem.com Sign In|Join Free

CAS

  • or

857760-44-2

Post Buying Request

857760-44-2 Suppliers

Recommended suppliersmore

  • Product
  • FOB Price
  • Min.Order
  • Supply Ability
  • Supplier
  • Contact Supplier

857760-44-2 Usage

Check Digit Verification of cas no

The CAS Registry Mumber 857760-44-2 includes 9 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 6 digits, 8,5,7,7,6 and 0 respectively; the second part has 2 digits, 4 and 4 respectively.
Calculate Digit Verification of CAS Registry Number 857760-44:
(8*8)+(7*5)+(6*7)+(5*7)+(4*6)+(3*0)+(2*4)+(1*4)=212
212 % 10 = 2
So 857760-44-2 is a valid CAS Registry Number.

857760-44-2Downstream Products

857760-44-2Relevant articles and documents

Non- C2-Symmetric Chiral-at-Ruthenium Catalyst for Highly Efficient Enantioselective Intramolecular C(sp3)-H Amidation

Zhou, Zijun,Chen, Shuming,Hong, Yubiao,Winterling, Erik,Tan, Yuqi,Hemming, Marcel,Harms, Klaus,Houk,Meggers, Eric

, p. 19048 - 19057 (2019/12/04)

A new class of chiral ruthenium catalysts is introduced in which ruthenium is cyclometalated by two 7-methyl-1,7-phenanthrolinium heterocycles, resulting in chelating pyridylidene remote N-heterocyclic carbene ligands (rNHCs). The overall chirality results from a stereogenic metal center featuring either a or Δabsolute configuration. This work features the importance of the relative metal-centered stereochemistry. Only the non-C2-symmetric chiral-at-ruthenium complexes display unprecedented catalytic activity for the intramolecular C(sp3)-H amidation of 1,4,2-dioxazol-5-ones to provide chiral -lactams with up to 99:1 er and catalyst loadings down to 0.005 mol % (up to 11 ?200 TON), while the C2-symmetric diastereomer favors an undesired Curtius-type rearrangement. DFT calculations elucidate the origins of the superior C-H amidation reactivity displayed by the non-C2-symmetric catalysts compared to related C2-symmetric counterparts.

Ruthenium(II)-Catalyzed Enantioselective ?-Lactams Formation by Intramolecular C-H Amidation of 1,4,2-Dioxazol-5-Ones

Xing, Qi,Chan, Chun-Ming,Yeung, Yiu-Wai,Yu, Wing-Yiu

, (2019/03/11)

We report the Ru-Catalyzed enantioselective annulation of 1,4,2-Dioxazol-5-Ones to furnish ?-Lactams in up to 97% yield and 98% ee via intramolecular carbonylnitrene C-H insertion. By employing chiral diphenylethylene diamine (dpen) as ligands bearing electron-Withdrawing arylsulfonyl substituents, the reactions occur with remarkable chemo- A nd enantioselectivities; the competing Curtius-Type rearrangement was largely suppressed. Enantioselective nitrene insertion to allylic/propargylic C-H bonds was also achieved with remarkable tolerance to the Ca?C and Ca‰iC bonds.

Synthetic Utility of N-Benzoyloxyamides as an Alternative Precursor of Acylnitrenoids for γ-Lactam Formation

Huh, Soohee,Hong, Seung Youn,Chang, Sukbok

supporting information, p. 2808 - 2812 (2019/04/17)

Described herein is the development of a new entry of acylnitrenoid precursors for γ-lactam synthesis via an intramolecular C-H amidation reaction. Upon Ir catalysis, N-benzoyloxyamides serve as efficient substrates to afford 5-membered amides. Mechanistic studies revealed that the generation of a putative Ir-carbonylnitrenoid via N-O bond cleavage is facilitated by the chelation of countercations. This protocol offers a convenient and step-economic route to γ-lactams starting from the corresponding carboxylic acids.

Post a RFQ

Enter 15 to 2000 letters.Word count: 0 letters

Attach files(File Format: Jpeg, Jpg, Gif, Png, PDF, PPT, Zip, Rar,Word or Excel Maximum File Size: 3MB)

1

What can I do for you?
Get Best Price

Get Best Price for 857760-44-2